In general, such a blind comprises a vertically-deployable panel made up of horizontal slats supported by ribbon ladders and terminated by a horizontal bottom end bar of position that is determined by means of at least two cords suitable for being wound on a horizontal driven roller of a top module that transforms rotary movement of a horizontal drive roller into rotary movement in a determined direction of said horizontal driven roller, as is well known in the art.
In general, each rung of the ribbon ladder carries a substantially horizontal blade that is tiltable about this relative horizontal direction in order to adjust its angle and obstruct the access of light to a greater or lesser extent.
Blinds of this type thus require a plurality of separate controls, in particular for raising or lowering the horizontal bottom bar and for tilting the blades. In conventional manner, these controls are separated in such a manner that one line serves to raise or lower the horizontal bottom bar, and another line serves to adjust the tilt of the blades.
That type of control using lines generally presents the drawback in that the lines easily become tangled together or twisted about each other.
Numerous attempts have been made to reduce this number of controls into a single control that is more practical for the user, and above all that can be operated remotely using simple electrical means. Examples can be found, amongst others, from the following documents: EP-A-1 213 438, EP-A-1 156 182, WO-A-01/27431, or U.S. Pat. No. 5,850,863.
Other types of such blinds are also described in the following documents: EP-A-1 072 753, EP-A-1 063 386, WO-A-02/95177, EP-A-1 170 458, and WO-A-02/57586.
None of the above-specified devices enables such a blind to be lowered or raised by the user performing the same simple action.